#include <stdlib.h>
#include <stdio.h>
#include <math.h>

struct sommet {
  double x;
  double y;
};

struct polygone {
  int ns;
  struct sommet* ts;
};

void afficherSommet(struct sommet s) {
  printf("%6.2lf%6.2lf", s.x, s.y);
}

double calculerDistanceSommets(struct sommet s1, struct sommet s2) {
  return sqrt(pow(s1.x - s2.x, 2.0) + pow(s1.y - s2.y, 2.0));
}

struct sommet creerSommet() {
  struct sommet s;
  s.x = (rand() % 101) / 100.0;
  s.y = (rand() % 101) / 100.0;
  return s;
}

double calculerPerimetrePolygone(struct polygone p) {
  double l = 0.0;
  for (int i = 0; i < p.ns - 1; i++) {
    l += calculerDistanceSommets(p.ts[i], p.ts[i + 1]);
  }
  l+= calculerDistanceSommets(p.ts[p.ns - 1], p.ts[0]);
  return l;
}

void afficherPolygone(struct polygone p) {
  printf("%d sommets\n", p.ns);
  for (int i = 0; i < p.ns; i++) {
    afficherSommet(p.ts[i]);
    printf("\n");
  }
}

struct polygone creerPolygone(int n) {
  struct polygone p;
  p.ts = (struct sommet*) calloc(n, sizeof(struct sommet));
  if (p.ts == NULL) {
    p.ns = 0;
  }
  else {
    p.ns = n;
    for (int i = 0; i < n; i++) {
      p.ts[i] = creerSommet();
    }
  }
  return p;
}

void detruirePolygone(struct polygone pl) {
  if (pl.ts != NULL) {
    free(pl.ts);
    pl.ts = NULL;
  }
}

void main(void) {
  srand(2);
  printf("%zu %zu\n", sizeof(struct polygone), sizeof(struct sommet));
  struct polygone pl = creerPolygone(5);
  printf("%zu\n", sizeof(pl));
  printf("\n");
  afficherPolygone(pl);
  printf("Perimetre : %lf\n", calculerPerimetrePolygone(pl));
  detruirePolygone(pl);
}